Recently, wearable devices which can be worn on the user's body have been developed. The user can operate the wearable devices to perform various functions.
The wearable device may include a battery for supplying power. To charge the battery, an electrode of the wearable device and an electrode of a charger can be connected to each other.
When the wearable device is being charged, the wearable device and the charger should be connected by electrodes having the same polarity in order to prevent the wearable device from being damaged by a short-circuit. To ensure that electrodes of the same polarity are connected, the wearable device may be required to connect to the charger in a certain orientation. But this may be inconvenient to the user because he or she must properly orient the wearable device and the charger in order to initiate charging.
In addition, when a separate electrode is added to the wearable device and the charger, various orientations are allowed when the wearable device is connected to the charger. However, in such circumstances, there is a possibility that unless the wearable device and the charger are completely fixed to each other, the wearable device may be damaged by a short-circuit caused by an external impact.